class_docstr: A named group membership.
  
  Args:
      id (None): the group ID
      name (None): the group name
code: def _id(self):
      return ObjectId(self.id)
  
file_path: fiftyone/fiftyone/core/groups.py
imports: from copy import deepcopy
  from bson import ObjectId
  import fiftyone.core.fields
  import fiftyone.core.odm
label_desc: Use image node_id 2 for calling the Group obj's underlying member method code with example usage: obj._id() and returns: ObjectId